The present invention relates to a multiple step-up rectifier circuit for rectifying an output voltage from the secondary winding of a transformer, and for boosting that voltage.
Various conventional multiple step-up rectifier circuits have been proposed. However, output voltages from these conventional circuits are relatively low. For this reason, the dielectric withstand voltage between primary and secondary windings of a transformer used in such a rectifier circuit may only be minimal.
Various compact power supply units with high-frequency arrangements have also been proposed, if only recently. A high-voltage power supply is not exceptional. The size of the high-voltage power supply tends to be decreased by the high-frequency arrangement. Even if a compact transformer is manufactured, the insulating gap between the primary and secondary windings of the transformer does not change, in principle. For this reason, linkage inductances of the primary and secondary windings are increased, depending on the size of the transformer. As a result, it is difficult to effectively induce a high voltage at the secondary winding. In particular, in a high-voltage transformer, corona discharge must be decreased to substantially zero, within the range of operating voltages, to achieve a long service life and high reliability. However, this is more difficult to achieve when an AC potential difference between the primary and secondary windings is increased.